||The default THROUGHPUT column in the files has been updated to the evaluation date for ETC 30.1, MJD 60035. These files will ensure that pysynphot calculations with no MJD specified will match results from ETC 30.1.
||Intrinsic excess thermal energy trapped in the silicon lattice of the WFC3 UVIS detector, known as dark current, is typically removed from science observations using UVIS dark calibration reference files. This dark current can be used as a means to characterize a pixels behavior and determine whether the pixel varies excessively over time compared to its expected noise. We use a novel data structure known as a pixel history image to efficiently evaluate each WFC3 UVIS pixel over time. We find that the vast majority of hot pixels, about 8 percent of the detector in 2021, are in fact quite stable and as such, can be calibrated. A small portion of pixels, less than 1.5 percent, are genuinely unstable and should not be used. To encode this distinction in the UVIS bad pixel reference files, we employ a data quality flag, 32, to mark the unstable pixels identified in this study. Hot pixels continue to be assigned the usual data quality flag, 16. With the additional data quality flag, WFC3 UVIS users will have enhanced control over which pixels to include or exclude during their analyses.
This new bad pixel table was generated using data taken from September 9th, 2021 through October 5th, 2021. Currently, the Calibration Reference Data System only has WFC3 UVIS bad pixel reference tables up to a USEAFTER date of August 11th, 2021. The automated pipeline should now use these reference files as the bad pixel table on any UVIS datasets obtained between the dates above, or beyond because they represent the most accurate measure of pixel stability at the time of the science observation. These WFC3 UVIS bpx files were generated using 900 second dark exposures from the HST Cycle 28 daily monitoring programs 16414 and 16396. More information about the UVIS bad pixel tables is outlined in the WFC3 ISR 2018.15 and WFC3 ISR 2021.14.
||The ACS WFC bias, dark, CTE dark, and sink files were generated following the ACS WFC anneal on Oct 11, 2021, and should be used to calibrate ACS WFC observations taken between Sep 13, 2021 and Oct 11, 2021.
||The COS FUV Throughput files for G130M cenwaves 1291, 1300, 1309, 1318, 1327 AND G140L cenwave 800 will be at LP5 and LP3, respectively in Cycle 29. The throughput files are being delivered for these cenwave modes ahead of ETC 30.1 .